This invention relates to a method of migrating data from a storage subsystem to another in a computer system. More specifically, this invention relates to a method of connecting a number of storage subsystems and migrating data from old storage subsystems to new ones without affecting a plurality of host computers.
IBM proposed Extended Remote Copy (XRC) and Peer-to-Peer Remote Copy (PPRC) to migrate data which are stored in a storage system and which a host computer is accessing (Implementing ESS Copy Services on S/390, IBM P. 502. 8. 5 DASD migration).
EMC proposed Symmetrix Data Migration Services (SDMS) (Symmetrix Data Migration Services, EMC Corporation, http://japan.emc.com/pdf/products/sdms/sdms_ds.pdf).